title: Poor reward sensitivity and apathy after stroke: implication of basal ganglia.
abstract: OBJECTIVE
  To examine the relationship between reward sensitivity and self-reported apathy in stroke patients and to investigate the neuroanatomical correlates of both reward sensitivity and apathy.
  
  
  METHODS
  In this prospective study, 55 chronic stroke patients were administered a questionnaire to assess apathy and a laboratory task to examine reward sensitivity by measuring motivationally driven behavior ("reinforcement-related speeding"). Fifteen participants without brain damage served as controls for the laboratory task. Negative mood, working memory, and global cognitive functioning were also measured to determine whether reward insensitivity and apathy were secondary to cognitive impairments or negative mood. Voxel-based lesion-symptom mapping was used to explore the neuroanatomical substrates of reward sensitivity and apathy.
  
  
  RESULTS
  Participants showed reinforcement-related speeding in the highly reinforced condition of the laboratory task. However, this effect was significant for the controls only. For patients, poorer reward sensitivity was associated with greater self-reported apathy (p < 0.05) beyond negative mood and after lesion size was controlled for. Neither apathy nor reward sensitivity was related to working memory or global cognitive functioning. Voxel-based lesion-symptom mapping showed that damage to the ventral putamen and globus pallidus, dorsal thalamus, and left insula and prefrontal cortex was associated with poorer reward sensitivity. The putamen and thalamus were also involved in self-reported apathy.
  
  
  CONCLUSIONS
  Poor reward sensitivity in stroke patients with damage to the ventral basal ganglia, dorsal thalamus, insula, or prefrontal cortex constitutes a core feature of apathy. These results provide valuable insight into the neural mechanisms and brain substrate underlying apathy.
authors.affiliation: From the Cognitive Psychopathology and Neuropsychology Unit (L.R., M.V.d.L.), Swiss Centre for Affective Sciences (L.R., M.V.d.L.), Methodology & Data Analysis (O.R.), and Department of Neuroscience, University Medical Center (R.S.), University of Geneva, Switzerland; Cognitive Psychopathology Unit (M.V.d.L.), University of Liège, Belgium; Neurology Unit (L.R., J.-B.E., L.S., J.-M.A.), Department of Medicine, Faculty of Sciences, University of Fribourg; and Department of Neurology (P.M.), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland.
authors.forename: Lucien
authors.initials: L
authors.lastname: Rochat
authors.forename: Martial
authors.initials: M
authors.lastname: Van der Linden
authors.forename: Olivier
authors.initials: O
authors.lastname: Renaud
authors.forename: Jean-Benoît
authors.initials: JB
authors.lastname: Epiney
authors.forename: Patrik
authors.initials: P
authors.lastname: Michel
authors.forename: Roman
authors.initials: R
authors.lastname: Sztajzel
authors.forename: Lucas
authors.initials: L
authors.lastname: Spierer
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Annoni
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology; D000368:Aged; D057565:Apathy / Q000502:physiology*; D001479:Basal Ganglia / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000502:physiology; D012044:Regression Analysis; D012189:Retrospective Studies; D012201:Reward; D020521:Stroke / Q000150:complications / Q000473:pathology / Q000523:psychology; D055815:Young Adult